JPH0710025Y2 - Particulate collector of engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a particulate collection device for an engine.

<Prior Art> Conventionally, in an engine, a so-called particulate trap filter having a large number of cells for collecting exhaust particulates (hereinafter referred to as particulates) contained in exhaust gas is interposed in an exhaust passage. ing.

By the way, when the collected particulates increase, the exhaust pressure increases due to the clogging of the filter, and the engine performance decreases.

For this reason, conventionally, a regeneration device such as a burner in which a heating unit is disposed on the upstream side of the filter is used to burn and remove the particulates trapped in the filter to regenerate the filter. (See JP 62-298615 A and JP 61-108821 B).

<Problems to be Solved by the Invention> By the way, since the filter has a configuration in which cells are alternately opened in the entire radial cross section, the particulates are collected substantially uniformly in each cell.

Therefore, when the filter is regenerated, the temperature of the central portion of the filter where the heat due to the combustion of the particulates is hard to escape becomes higher than that of the outer peripheral portion, and the following problems occur.

That is, the central part of the filter becomes hot and melts. Further, the temperature difference between the central portion and the outer peripheral portion of the filter becomes large, and cracks in the filter occur. Further, the central portion of the filter is reproduced before the outer peripheral portion, and the outer peripheral portion cannot be effectively reproduced, so that uniform reproduction cannot be performed.

The present applicant has previously proposed, as a technique for solving the above-mentioned drawbacks, a filter device having a configuration in which the filter cell is formed such that the cell passage area is small in the central portion and increases toward the outer periphery. (See Japanese Patent Application No. 63-6075).

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to prevent the above-mentioned conventional problems from occurring by avoiding an excessive temperature rise in the center of the filter during regeneration.

<Means for Solving the Problems> Therefore, according to the present invention, a heating unit of a filter regenerator for arranging a particulate filter having a large number of cells in an exhaust passage and burning and removing the collected particulates. In the particulate trapping device of the engine having a structure in which the filter is arranged on the upstream side of the filter, the filter is selectively provided at a closed position for closing a cell opening end located at a substantially central portion of an upstream end face of the filter and an open position for opening the cell opening end. An opening / closing cover that can be operated is provided.

<Operation> In such a configuration, at the time of collection, the open end of the cell, which is open at the center of the upstream end face of the filter, is closed by the open / close cover to be collected in the cell formed at the center of the filter. The amount of particulates is greatly reduced. As a result, when the filter is regenerated, it is possible to prevent the temperature of the central portion of the filter from excessively rising due to the combustion heat of the particulates.

Therefore, it is possible to prevent the melting of the central portion of the filter and the crack of the filter from occurring, and it is possible to uniformly reproduce the entire filter.

During regeneration, the cell opening end, which is open at the center of the upstream end face of the filter, is opened by the open / close cover, so that the heat generated at the outer peripheral portion of the filter can be released to the outside through the center.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, a particulate trap filter 2 is provided in an exhaust pipe 1 which constitutes an exhaust passage. The particulate trap filter 2 is housed in a cylindrical filter case 3 with a cylindrical sealing material 4 interposed therebetween. This particulate trap filter 2
It has a honeycomb structure formed of a porous material such as ceramic and having a large number of cells 2a. That is, the upstream side opening end faces of a large number of cells 2a formed in the filter 2 in a lattice pattern are vertically and horizontally filled with alternating fills 5. On the downstream end face of the filter 2, the cells 2a whose upstream end face is not clogged 5 are clogged.

Here, the cell 2a located in the central portion on the upstream side of the filter 2
An opening / closing cover that is selectively operated is provided in a closed position that closes the open end and an open position that opens.

That is, as shown in FIGS. 1 and 2, there is provided a single circular opening / closing cover 8 for collectively opening / closing the open ends of the cells 2a opened at the center of the upstream end face of the filter.

In this case, the cover 8 is fixed to the rotary shaft 8a whose both ends are rotatably supported on the inner peripheral surface of the exhaust pipe, and the cover 8 is rotated between the open position and the closed position by the rotary operation of the rotary shaft 8a. I am trying to move it.

In the structure shown in FIG. 3, the cover 8 is fixed to a swing shaft 8b whose one end is swingably supported in the front-rear direction in a filter case, and the cover 8 is swingable by this swing shaft 8b. Is swung back and forth between the open position and the closed position.

Further, in the structure shown in FIG. 4, the cover is composed of semicircular cover divisions 8A and 8B, and both ends of the cover divisions 8A and 8B are rotatably supported on the inner peripheral surface of the exhaust pipe. It is fixed to a pair of rotating shafts 8c and 8d arranged in parallel, and by the rotating operation of these rotating shafts 8c and 8d, the cover divided bodies 8A and 8B are rotated to the open position and the closed position, respectively.

In such a structure, when collecting the particulates, the cover 8 is closed and the open end of the cell 2a opened at the center of the upstream end face of the filter 2 is closed. The amount of collected particulates can be significantly reduced. On the other hand, at the time of regeneration of the filter 2, the cover 8 is opened to open the open end of the cell 2a at the center of the upstream end surface of the filter 2, and the combustion gas is also circulated to the cell 2a at the center.

Therefore, according to such a configuration, when the filter 2 is regenerated,
It is possible to prevent the temperature of the central part of the filter 2 from rising excessively due to the combustion heat of the particulates, and especially when the filter 2 is regenerated, the combustion gas is also supplied to the cell 2a at the center of the upstream end face of the filter 2. Filter 2 for distribution
The heat generated in the outer peripheral portion of the can be released to the outside through the central portion. That is, the central part of the filter 2 does not become a heat generating part but a heat radiating part.

As a result, the temperature distribution of the filter 2 can be made substantially uniform in the central portion and the outer peripheral portion.

Therefore, the central portion of the filter 2 is prevented from melting and the filter 2 is prevented.
It is possible to more effectively prevent the generation of cracks and uniformly reproduce the entire filter 2.

The graph of FIG. 5 shows an example of the amount of collected particulates and the temperature of the filter 2 at the time of regeneration with respect to each position of the filter 2. The dotted line shows the conventional example and the solid line shows the present invention. From this graph, it is clear that the amount of collected particulates is small in the central portion of the filter 2, and the central temperature of the filter 2 during regeneration is suppressed to, for example, the melting temperature of the filter 2 or less.

In each of the above embodiments, the present invention is applied to the trapping device configured to regenerate the filter 2 when the exhaust gas does not flow, that is, when the engine is stopped. The present invention can also be applied to a collection device that is sometimes used.

This collector is configured as shown in FIGS. 6 and 7, for example.

In FIG. 6, the exhaust pipe 1 is provided with a bypass pipe 9 that bypasses the particulate trap filter 2, and switching valves 10 are provided at the inlet and outlet of the bypass pipe 9, respectively. is there.

With this configuration, when collecting particulates, the switching valve 10 is set to the position shown by the solid line to allow the exhaust gas to flow to the filter 2 side, and when the filter 2 is regenerated, the switching valve 10
10 is set at the position indicated by the point so that the exhaust gas is allowed to flow to the bypass pipe 9 side.

On the other hand, the one shown in FIG. 7 is provided with a branch pipe 11 branched from the upstream side of the particulate trap filter 2 of the exhaust pipe 1, and a switching valve 12 at the inlet of the branch pipe 11.

In this configuration, when collecting particulates, the switching valve 12 is set to the position shown by the solid line so that the exhaust gas is circulated to the filter 2 side, and when the filter 2 is regenerated, the switching valve 12 is set.
12 is set to the position shown by the dotted line so that the exhaust gas is allowed to flow to the side of the branch pipe 11.

<Effects of the Invention> As described above, according to the party accurate trapping device for an engine of the present invention, the closed position and the open position for closing the cell open end located substantially in the center of the upstream end face of the filter are opened. Since the opening / closing cover that is selectively operated is provided at the position, the opening / closing cover closes the cell opening end that is open at the center of the upstream end face of the filter at the time of collection and the filter opening at the time of regeneration. By opening the cell opening end, which is open at the center of the upstream end face, with the open / close cover, it is possible to prevent the temperature of the filter central portion from rising excessively due to the combustion heat of the particulates, and to prevent The heat generated in the outer peripheral part can be released to the outside through the central part, and the temperature distribution of the filter can be made substantially uniform between the central part and the outer peripheral part. This is a great practical effect that can prevent melting damage of the core part, prevent cracking of the filter, and uniformly reproduce the entire filter.

[Brief description of drawings]

1 is a front sectional view showing an embodiment of an engine particulate trapping device according to the present invention, and FIGS. 2 to 4 are schematic perspective views showing an embodiment of an opening / closing cover of the present invention, respectively. FIG. 6 is a graph showing the effect of the present invention in comparison with a conventional example, and FIGS. 6 and 7 are schematic views of other particulate trapping apparatuses for carrying out the present invention. 1 ... Exhaust pipe, 2 ... Particulate trap filter, 2a ... Cell, 8 ... Cover

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Asami, 1-chome, Ii-chome, Ageo-shi, Saitama, Nissan diesel industry Co., Ltd. (72) Tadashi Ishii 1-chome, Io-chome, Ageo, Saitama Prefecture Incorporated (56) References Actually open Sho 61-149714 (JP, U) Actually open 63-19021 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A particulate filter having a structure having a large number of cells in an exhaust passage, and a heating unit of a filter regenerator for burning and removing the collected particulates is arranged upstream of the filter. In the particulate trapping device of the engine, an opening / closing cover that is selectively operated in a closed position that closes the cell opening end located at substantially the center of the upstream end surface of the filter and an open position that opens is provided. A particulate collection device for the engine.